In all Cases affecting Ambassadors, other public Ministers and Consuls, and those in which a State shall be Party, the supreme Court shall have original Jurisdiction. In all the other Cases before mentioned, the supreme Court shall have appellate Jurisdiction, both as to Law and Fact, with such Exceptions, and under such Regulations as the Congress shall make. (emphasis added)

Let us now examine in what manner the judicial authority is to be distributed between the supreme and the inferior courts of the Union. The Supreme Court is to be invested with original jurisdiction, only “in cases affecting ambassadors, other public ministers, and consuls, and those in which A STATE shall be a party. ” Public ministers of every class are the immediate representatives of their sovereigns. All questions in which they are concerned are so directly connected with the public peace, that, as well for the preservation of this, as out of respect to the sovereignties they represent, it is both expedient and proper that such questions should be submitted in the first instance to the highest judicatory of the nation. Though consuls have not in strictness a diplomatic character, yet as they are the public agents of the nations to which they belong, the same observation is in a great measure applicable to them. In cases in which a State might happen to be a party, it would ill suit its dignity to be turned over to an inferior tribunal. (emphasis added)

(a) The Supreme Court shall have original and exclusive jurisdiction of all controversies between two or more States.
(b) The Supreme Court shall have original but not exclusive jurisdiction of:

(1) All actions or proceedings to which ambassadors, other public ministers, consuls, or vice consuls of foreign states are parties;(2) All controversies between the United States and a State;
(3) All actions or proceedings by a State against the citizens of another State or against aliens. (emphasis added)